In modern microscopy, particularly in the high-end range, many optically high-quality objectives are calculated and designed such that they only operate optimally if the gap between the front lens of an objective and the preparation to be observed is filled with a so-called immersion medium. Due to its optical properties which resemble those of glass more than those of air, this immersion medium has the purpose of providing improved optical properties during imaging. However, with a microscope with incubation means or other attachment parts placed in the surroundings of the object, the manual application of this immersion medium is very elaborate. In addition, it is very difficult for the operator to evaluate the condition of the immersion since, as a rule, it is very difficult or impossible to examine. In fact, access or control in automated microscopes may be entirely impossible since the entire microscope is enclosed in a housing.
DE 102006042088 B4 describes a device and a method for forming an immersion film between a lens of a microscope objective and a sample carrier with an element attached to the objective which defines the immersion film region. With a sensor unit, the state of the immersion film in the immersion film region is detected. The supply of the immersion is controlled on the basis of the state of the immersion film. This solution is disadvantageous because the sensor unit attached to the objective has a negative impact on the structure of the microscope.
Furthermore, JP 2012093387 A2 describes a microscope system in which the immersion fluid is detected by evaluating the focal coordinate. This takes advantage of the fact that the focal coordinate moves if the immersion fluid is compromised, since the focal point of the microscope objective shifts without an immersion fluid. Determining the focus displacement with this solution, however, is very complicated.
Proceeding from the solutions of the prior art, the invention addresses the problem of further developing a method for detecting and controlling supply of an immersion medium such that, without additional hardware components specifically developed for such purpose, independently from the ambient parameters such as filling level of the system or point of time of the last immersion, the supply of the immersion fluid can be controlled such that the required amount is always available in the immersion film region.